This introduces the main precheck logic. This will follow concurrency model, timeout handling, and retry logic established in the SPEC. We will follow the decision flow in the [connectivity pre-checks SPEC](https://wiki.cfdata.org/spaces/TUN/pages/1374967685/Connectivity+Pre-checks+for+cloudflared). You can find an attached image of what the decision flow should look like.
{width=900 height=235}
Switching `SuggestedProtocol` to a pointer, so we can pass nil whenever both QUIC and HTTP2 fail. We should not be suggesting anything when all our protocols have failed.
The goals of this PR are twofold:
## **1. Introduce a new renderer to output to `stdout`**
Implement the table renderer that will be used to report the results to stdout. The renderer should output something similar to this:
```
─── CONNECTIVITY PRE-CHECKS ──────────────────────────────────────────────────
COMPONENT TARGET STATUS DETAILS
DNS Resolution region1.v2.argotunnel.com PASS Resolved successfully
DNS Resolution region2.v2.argotunnel.com PASS Resolved successfully
UDP Connectivity Port 7844 (QUIC) PASS Handshake successful
TCP Connectivity Port 7844 (HTTP/2) PASS TLS handshake successful
Cloudflare API api.cloudflare.com:443 PASS Reachable
SUMMARY: Environment is healthy. cloudflared will use 'quic' as primary protocol.
──────────────────────────────────────────────────────────────────────────────
```
## **2. Add a log-level renderer**
Add support for structured logging to print the table results as logs. Below is an example of how logs should look like:
```
{"level":"info","run_id":"52828729-dfwd-45b3-w12f-727cbdb4cbd4", "component":"DNS Resolution","target":"region1.v2.argotunnel.com","status":"pass","details":"Resolved successfully","time":"2024-01-15T10:30:00Z","message":"precheck"}
{"level":"info","run_id":"52828729-dfwd-45b3-w12f-727cbdb4cbd4", "component":"DNS Resolution","target":"region2.v2.argotunnel.com","status":"pass","details":"Resolved successfully","time":"2024-01-15T10:30:00Z","message":"precheck"}
{"level":"info","run_id":"52828729-dfwd-45b3-w12f-727cbdb4cbd4", "component":"QUIC Connectivity","target":"Port 7844 (QUIC)","status":"pass","details":"Handshake successful","time":"2024-01-15T10:30:01Z","message":"precheck"}
{"level":"info","run_id":"52828729-dfwd-45b3-w12f-727cbdb4cbd4", "component":"HTTP/2 Connectivity","target":"Port 7844 (HTTP/2)","status":"pass","details":"TLS handshake successful","time":"2024-01-15T10:30:01Z","message":"precheck"}
{"level":"info","run_id":"52828729-dfwd-45b3-w12f-727cbdb4cbd4", "component":"Management API","target":"api.cloudflare.com:443","status":"pass","details":"Reachable","time":"2024-01-15T10:30:01Z","message":"precheck"}
{"level":"info","run_id":"52828729-dfwd-45b3-w12f-727cbdb4cbd4", "hard_fail":false,"suggested_protocol":"quic","time":"2024-01-15T10:30:01Z","message":"precheck complete"}
```
This adds the foundation for the new cloudflared pre-checks by creating a new prechecks package. This adds the following:
* types.go: Status, CheckResult, Report, Config (add IPVersion allregions.ConfigIPVersion field to Config)
* interfaces.go: DNSResolver, TCPDialer, QUICDialer, ManagementDialer
